This week, discounts on games played a huge part in the sales on Steam. The release of Call of Duty: Black Ops topped the Steam list, but that doesn't compare to the rest of the list, which was populated by great deals on great games. Warhammer 40K, Left 4 Dead 2, Team Fortress 2, and Worms Reloaded got their individual prices halved, while Bioshock and the S.T.A.L.K.E.R. Bundle, some of the better games of 2007, got a 75% off discount. Everything else sold either from current popularity or pre-release buzz. Call of Duty will stay on the list for a while, though Bioshock will fall off the second it gets normal pricing again.